Torque converter regulator and clutch lockout system for an automotive vehicle

Abstract

A system for controlling operation of a bypass clutch for a torque converter in an automatic transmission includes a clutch capacity control valve, which connects a source of fluid pressure to a space between a converter clutch friction surface and an impeller casing in response to a force balance produced by variable pressure control signal and an unlock control pressure signal, produced by a converter lockout valve. The a clutch capacity control valve also supplies pressurized fluid to a torus of the torque converter. The valve includes four control lands connecting 10 ports, all of which are active and independent.

What is claimed is: 
     
       1. A system for controlling locked and unlocked operation of a converter clutch, comprising: a torque converter having an impeller, turbine and stator defining a toroidal fluid flow path, a converter clutch for driveably connecting and releasing the impeller and turbine;   a first line for supplying pressurized fluid to a first side of the converter clutch;   a second line for venting and pressurizing a second side of the converter clutch;   a vent port;   a source of converter feed pressure;   lockout means for producing converter unlock pressure having a first magnitude representing a command to unlock the converter and a second magnitude representing a command to lock the converter;   a source of converter control pressure producing a variable pressure including a third magnitude representing a command to unlock the converter and a fourth magnitude representing a command to lock the converter;   a converter regulator valve means for unlocking the converter clutch by opening a connection between the source of converter feed pressure and the first and second lines when the lockout means produces the first magnitude, or the lockout means produces the second magnitude and the source of converter control pressure produces the third magnitude, and for locking the converter clutch by opening a connection between the source of converter feed pressure and the first line and between the second line and the vent port when the lockout means produces the second magnitude and the source of converter control pressure produces the fourth magnitude.   
     
     
       2. The system of claim 1 wherein the lockout means comprises a lockout valve including: a source of actuating pressure communicating with the lockout valve;   a third line connecting the lockout valve and converter regulator valve means;   a spool having control lands on which first pressure forces representing a requirement that the converter clutch be unlocked and second pressure forces representing a requirement that the converter clutch be locked are developed in mutual opposition;   means for opening and closing a connection between the source of actuating pressure and the third line in response to the relative magnitude of the first and second pressure forces.   
     
     
       3. The system of claim 2 wherein a connection between the source of actuating pressure and third line is opened when the first pressure forces exceed the second pressure forces, and a connection between the source of actuating pressure and third line is locked when the first pressure forces exceed the second pressure forces. 
     
     
       4. The system of claim 1 wherein the converter regulator valve means comprises: a valve body defining a valve chamber, communicating with the source of converter feed pressure, first line, second line and vent port;   a spool slidable in the valve chamber, having multiple control lands including a first control land communicating with the source of converter control pressure and adapted to have a control force applied thereto, a second control land communicating with the lockout means and adapted to have a control force applied thereto, a third control land adapted to open a connection among the source of converter feed pressure, first line, and second line when the spool moves to a position corresponding to unlocked converter clutch operation in response to control forces applied to the spool corresponding to unlocked converter clutch operation, and adapted to open a connection between the vent port and second line and to open a connection between converter feed pressure and first line when the spool moves to a position corresponding to open converter clutch operation in response to control forces applied to the spool corresponding to locked converter clutch operation.   
     
     
       5. The system of claim 4 wherein the converter regulator valve means further comprises a compression spring biasing the spool toward a position corresponding to unlocked converter clutch operation. 
     
     
       6. A system for controlling locked and unlocked operation of a converter clutch, comprising: a torque converter having an impeller, turbine and stator defining a toroidal fluid flow path, a converter clutch for driveably connecting and releasing the impeller and turbine;   a first line for supplying pressurized fluid to a first side of the converter clutch;   a second line for venting and pressurizing a second side of the converter clutch;   a source of converter feed pressure;   lockout means for producing converter unlock pressure having a first magnitude representing a command to unlock the converter and a second magnitude representing a command to lock the converter;   a source of converter control pressure producing a variable pressure including a third magnitude representing a command to unlock the converter and a fourth magnitude representing a command to lock the converter;   a converter regulator valve means comprising: a valve body defining a valve chamber, communicating with the source of converter feed pressure, first line, second line and a vent port;   a spool slidable in the valve chamber, having multiple control lands including a first control land communicating with the source of converter control pressure and adapted to have a control force applied thereto, a second control land communicating with the lockout means and adapted to have a control force applied thereto, a third control land adapted to open a connection among the source of converter feed pressure, first line, and second line when the spool moves to a position corresponding to unlocked converter clutch operation in response to control forces applied to the spool corresponding to unlocked converter clutch operation, and adapted to open a connection between the vent port and second line and to open a connection between converter feed pressure and first line when the spool moves to a position corresponding to locked converter clutch operation in response to control forces applied to the spool corresponding to locked converter clutch operation.     
     
     
       7. The system of claim 6 wherein the converter regulator valve means further comprises a compression spring biasing the spool toward a position corresponding to unlocked converter clutch operation.